It says new authors should reflect the UK population by 2025, "taking into account ethnicity, gender, sexuality, social mobility and disability".

The company said: "Books shape our culture, and this should not be driven only by people who come from a narrow section of society."

It has also said job applicants would no longer need to have a degree.

The We Need to Talk About Kevin author said the publishers were "drunk on virtue".

Writing in the Spectator, Ms Shriver said: "Penguin Random House no longer regards the company's raison d'être as the acquisition and dissemination of good books.

"Rather, the organisation aims to mirror the percentages of minorities in the UK population with statistical precision."

In the article she suggested that a manuscript "written by a gay transgender Caribbean who dropped out of school at seven" would be published "whether or not said manuscript is an incoherent, tedious, meandering and insensible pile of mixed-paper recycling".

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Ms Shriver also said she found it "alarming" that the publishing house was no longer requiring new staff to have degrees.